Used as an adjective to describe a movie (usually a super-hero movie) with a love interest that ruins the plot of the film thus making the film crap.

Usually the plot will center around the love interest in the hope audiences will relate to the character. So the character is stereotypically from Earth, white and female, as well as a Jew however this last factor is unrelated.

Some unforeseen consequences of adding this character is that she will take away a considerable amount of screen time for herself with mainly non-action sequences, have to be added into sequels and could force the movie to come to Earth at some point even when the film would be better if it instead had more action sequences. Worse still is that the love interest will usually bring other characters into the fold that are in some way retarded or a comical relief.

The term Ghost Rider can also be substituted for Natalie Portman to describe the same movie, however the movie is usually all round terrible not only due to the love interest.

Days of future past was pretty good, at least they didn't Natalie Portman it.

or

Thor 2 was even more Natalie Portman than the first. Why do they keep doing that?